Addiction is simply defined as engaging in the continued use of substances or activities in the face of negative consequences. Addiction appears to result from a combination of precipitating environmental factors and underlying biological risk factors, similar to other neurobehavioral disorders, like schizophrenia or depression. The biological mechanisms of addiction have been explored in great detail, uncovering much about the neurobiology of drug self-administration and effects of chronic drug exposure (Everitt et al., 2007; Jentsch and Taylor, 1999; Robinson and Berridge, 2003). However, the cognitive aspects of addiction remain relatively unexplored despite converging evidence that perturbation of cognitive control is a hallmark of addiction (Ersche et al., 2005; Garavan and Stout, 2005; Wilson et al., 2007). As cognitive control is commonly considered the domain of the frontal lobes, there is growing interest in frontal lobe investigations in the context of addiction. Moreover, there are similarities in behavior between addicted individuals and patients with PFC damage. For example, damage to the human OFC (Berlin et al., 2004), but not the ventromedial frontal lobe (Fellows and Farah, 2005), increases the tendency to
